[HN Gopher] RNA forms on basalt lava glass in the presence of nu...
___________________________________________________________________
RNA forms on basalt lava glass in the presence of nucleoside
triphosphates
Author : sanketpatrikar
Score : 301 points
Date : 2022-06-05 07:34 UTC (15 hours ago)
(HTM) web link (www.liebertpub.com)
(TXT) w3m dump (www.liebertpub.com)
| Traubenfuchs wrote:
| Isn't RNA on its own useless?
|
| Doesn't it need the cells molecular machines to execute it?
|
| This seems to be the computer equivalent to: Cosmic rays formed a
| hello world program on this memory chip in my drawer.
| flobosg wrote:
| RNA molecules can act as catalysts. See
| https://en.wikipedia.org/wiki/Ribozyme
| JPLeRouzic wrote:
| How this fits in the RNA world hypothesis?
| gus_massa wrote:
| It's in favor of the RNA word hypothesis, because it gives a
| possible explanation of how the first RNA was formed.
|
| IIRC there are other proposed methods to produce RNA. IIUC this
| method assumes that there are many triphosphates floating
| around, that is possible but needs another explanation.
|
| So IMHO it's just a tiny step in the right direction, but not a
| "breakthrough" like some press articles claim.
| JPLeRouzic wrote:
| Thanks for the explanation!
| begueradj wrote:
| I will read this later
| oyebenny wrote:
| From the ashes we rise
| lynguist wrote:
| Your comment made me think about what is the principal point of
| evolution:
|
| New ideas/species/functions are not born from competition, they
| are formed by mixing up.
| BiteCode_dev wrote:
| And filtering.
| greenbit wrote:
| I think the whole RNA thing is a bit over hyped. People like RNA
| because it looks somewhat like computer code, and our technology
| is just smitten with computers, these recent decades. And right
| along with that, it makes for such a painfully obvious way to
| implement inheritance and natural selection, a way to make genes.
|
| But I think our focus is too narrow, we should think bigger than
| just obvious solutions. Now, it's great if the early oceans were
| awash with RNA, but does RNA exploit energy gradients on its own?
| The idea of all this random RNA just sloshing around, using
| nothing more than entropy, behaving as genes and inventing all
| the rest of it, just seems a little cart-before-the-horse.
|
| What about metabolism-first? Is fire alive? It has many
| properties of life but, critically, lacks self regulation and
| heritability. Burns everything and goes out. Imagine though, a
| system of enzymes that can assimilate various specific kinds of
| molecules, and sustain production of those enzymes. Imagine this
| contained, compartmentalized in some way. Dynamically not much
| more complicated than simple fire, but crucially, the enzymes can
| be said to be inherited. These are not 'genes' as such, these are
| the actual machinery. It should be possible for natural selection
| to act on 'life' no more complicated than that. And that kind of
| system could then take find uses for RNA.
|
| (And yes, the enzymes I refer to could be realized as RNA, but
| acting as the enzymes directly, not merely describing them, and
| this would confer some major benefits)
| greenbit wrote:
| Some afterthoughts:
|
| In seeking abiogenesis what we're really looking for is the
| first replicators. Certainly RNA strands can self replicate,
| but how is a particular sequence _alive_? About as alive as a
| virus, perhaps. Ok, posit a whole world of naked RNA, with
| multitudes of different sequences. Has life arrived on such a
| world? I 'd say the interesting event would still be downstream
| from there, when by chance some of those different sequences
| happened to cooperate to mutual advantage. But that's like
| viruses inventing the cell.
|
| Whereas, if you allow for the spontaneous collaboration of mere
| enzymes to create self sustaining metabolism, you can get a
| system that should exhibit natural selection, even without
| genes.
|
| I guess what I'm railing on about is this notion that we have
| one class of molecules that do the work, and another that
| merely describes other molecules. We create categories and
| labels for what we see, and then get stuck within those
| constructs. Truth is often more subtle.
| robbiep wrote:
| You know RNA can work as enzymes right?
|
| You're basically saying 'let's create some other form that
| was doing the work' - which could be true - weird small
| crevices with certain molecular properties and different
| metals exposed to heat gradients where 'the soup' tidally
| comes and goes and catalyses reactions - and maybe that was
| an important step, but you're also overly easily dismissing
| something that not only can act as that first step (maybe
| with some help from some unknown catalyst as a bootstrap)
| with the added benefit of actual inheritance
| lupire wrote:
| Life is not a binary. Life is a gradient of complexity.
| Ultimatt wrote:
| RNA does all of those functions, thats why people think it
| was prevalent before DNA. There are very few DNA enzymes
| compared to RNA. RNA provides structure in complex with other
| molecules which is indirectly catalytic to their activity, as
| well as being catalytic directly from its own folded
| structure, then you also have coded information representing
| its own structure but later those of proteins with the
| establishment of the genetic code. But you have to remember
| ribosomes have to exist for the genetic code to mean
| anything, or at least whatever ribosomes looked like at the
| start, which is very likely just RNA and a couple of
| peptides.
| ianai wrote:
| Saw a video on YT that I think was saying what you just
| described might eventually build up a living cell. That
| would be pretty huge.
| flobosg wrote:
| > And yes, the enzymes I refer to could be realized as RNA, but
| acting as the enzymes directly, not merely describing them
|
| RNA can act as an enzyme
| (https://en.wikipedia.org/wiki/Ribozyme). This fact is one of
| the arguments in favor of the RNA world hypothesis.
| ramraj07 wrote:
| It's often hard to tell between a genius who's so far out away
| from others that what they say doesn't make any sense or
| someone who has no clue what's actually known about something.
| I'll give that benefit of doubt to you but suffice to say I
| have no idea what you're talking about.
|
| The rna hypothesis is not overhyped. The fact of the matter is
| rna looks like a likely candidate that can form in the
| conditions of early earth, and it's a perfect candidate for a
| single molecule that can become self replicating. We don't know
| the math of the probability that this thing happened and how
| big an experiment volume we had in terms of environment size
| and time span, so hard to tell if this happened this way or
| not. Suffice to say I see no other plausible hypothesis
| proposed that is as believable as the RNA world. At least
| something I can understand anyway.
|
| FWIW I do believe in the RNA world hypothesis only I don't
| think it happened in earth, but some other planet at some point
| in past. I just think that space is filled with floating frozen
| microbial spores that can instantly (geologically speaking)
| inoculate any planet with the right conditions.
| greenbit wrote:
| what I'm saying is,
|
| RNA, great, that's a Thing. I just don't think that finding a
| mechanism for RNA to arise is the big step. I think the Big
| Step is going to be discovery of a set of molecules that use
| what's available to make more of that set.
|
| Could the molecules in that set be RNA? Sure! Do they _have_
| to be RNA? I have no idea. How small can that set be? Can it
| be a single molecular species? That would be fascinating! I
| 'd think it would probably take more than one, though.
|
| I'm not trying to rain on anyone's parade, just trying to
| stir the pot of ideas.
| ramraj07 wrote:
| So wait, you think there could be a potentially simpler
| system than a SINGLE MOLECULE OF RNA that is self
| replicating (I.e. if all you provide is a chemical solution
| with the raw base ingredients it can build more of itself
| with no other help)? That's awesome. Please share, no
| hyperbole intended, what your hypothesis is.
|
| But that doesn't change the fact that RNA world fits the
| most amount of our observations. I already described
| proving it's plausibility in our experiments. On top of
| that please don't forget that ribosomes, the complexes that
| produce proteins in our body, are mostly RNA, and the rna
| part is the primary enzymatic system in it. That is, we
| actually have a vestige of a system where rna ruled the
| world.
|
| I'm not even asking you for proof, I'm asking you to even
| put forward an actual molecular system that you think is
| better suited to explain this than rna.
| uplifter wrote:
| Not the GP but maybe I can help elucidate the position
| they're representing. The GP advocates for what is known as
| the "metabolism-first" hypothesis in origins of life theory.
| The motivation of this theory that some chemists and
| biologists find it implausible that a self-catalyzing RNA
| based biological machinery would have formed spontaneously
| from a collection of basic precursor chemicals, even given
| very long spans of time and large volumes of precursors. They
| believe this because nucleic acids are very complex
| structures and themselves require very complex biologic
| machinery to assemble, and their understanding of the
| likelihood of chemical reactions suggests its unreasonable to
| expect them to form in geological time spans. They posit that
| instead its more likely that nucleic acid based systems were
| themselves preceded by system(s) composed of sets of simpler
| chemicals (ones which are likely to form spontaneously) which
| together catalyze each other's formation (a so-called "auto-
| catalytic set"), and that this era of simple metabolisms
| eventually produced a nucleic acid based system which
| completely overtook and replaced/assimilated the more
| primitive auto-catalytic set world.
|
| Here's a primer on the metabolism-first hypothesis:
| https://www.statedclearly.com/videos/what-is-the-
| metabolism-...
| ramraj07 wrote:
| Thanks for the reference. As the other commenter mentioned,
| this is great research but I don't see it as with odds with
| a molecule of RNA being the first living thing ever. We
| didn't discuss before what powered these RNA molecules, but
| clearly this research is showing us one aspect of it
| (preexisting metabolic pathway like reactions). These
| systems might be considered as evolving the same way the
| sun is evolving I suppose? In the end I would classify life
| as something that has encoded information on how to create
| itself and the machinery to do it (or at least the means to
| recruit the machinery and raw materials) and actually
| propagate itself perpetually in the right conditions. RNA
| is still the only viable candidate for that.
| Ultimatt wrote:
| RNA first is about stored heritable genetic information? At
| least I've not met anyone who's in some hardline way RNA
| miraculously appears and starts creating the auto catalytic
| networks second. How does the RNA appear? Slowly at random
| from nothing? Why would anyone think this, it doesn't pass
| thought experiment level parsimony. The reason to highlight
| RNA first is because if you just looked at whats alive now
| you might assume DNA is the older molecule in use as its
| the primary store of genetic information for most things
| alive right now. The big idea is that it wasn't. That
| doesn't mean everyone means its the first molecule to exist
| in the history of molecular life...
| uplifter wrote:
| You seem to already know this, but "Metabolism First" is the
| name used for the theory in biology that you just described[0]
|
| The idea is that some self-catalyzing cycle(s) of reactions
| among chemicals structurally much simpler than nucleotides or
| even protein enzymes preceded the era of nucleic acid based
| biology, until being completely (or replaced) by said RNA/DNA
| based systems.
|
| [0] Metabolism First primer:
| https://www.statedclearly.com/videos/what-is-the-metabolism-...
| tetris11 wrote:
| It's not quite a random soup though, RNA folding usually tries
| to minimize the energy exerted during the folding and binding
| process, no? Isn't this similar with fire, and enzymes, and
| other unconscious actors that appear to exhibit complex
| behavoirs but are just minimising some energy gradient?
| greenbit wrote:
| I'm just painting broad strokes, trying to avoid the TL;DR
| threshold.
|
| But re energy gradients, I'm talking about the difference
| between being able to tap into potential energy in the
| environment, vs just seeking some kind of equilibrium. Sure,
| a freshly crafted sequence of amino acids will find a shape
| to minimize the internal energy, and so you can say there's a
| gradient there, but that's different from taking in H2S and
| CO2 (or what have you) from the environment and reacting them
| to liberate non-thermal energy that can be used to get things
| done.
| Ultimatt wrote:
| greenbit so in your mind what is a viroid? We have examples
| that are extant of RNA doing this. Sure its exploiting an
| established RNA system, but the point still stands as
| there's absolutely no reason you couldn't have viroids
| dealing with other catalytic networks making RNA. That's
| sort of the point, at some point everything was wandering
| viroids among autocatalytic networks with varying survival
| rates. That gets you selective pressure. Thats the
| transition you're talking about, from autocatalytic
| localised chemistry into RNA. The initial fitness benefit
| of RNA is that for one class of molecule you can have a lot
| of complex catalytic chemistry AND they have the ability
| through base pairing to catalyse their own _exact_
| replication.
| topher515 wrote:
| If you haven't read "The Vital Question" by Nick Lane yet, then
| you really should.
|
| One of the book's suggestions is that an energy-first analysis
| of life and the origins of life, can be incredibly explanatory
| --particularly since Science (and Pop-Science) has been so
| focused on genetics for so long.
|
| In terms of the origins of life, the idea is essentially that
| rather than try to imagine how RNA could "just appear", we
| should look for places where there were natural, persistent,
| energy fluxes (the "fires" as you say), and try to understand
| how these energy fluxes began to resemble cells. i.e., were
| constrained into cell-sizes and began replicating.
|
| Incidentally, the theory that Nick Lane puts forward of which
| particular energy fluxes gave rise to life is sea-floor
| alkaline hydrothermal vents[1]--which is also discussed in the
| book.
|
| [1] https://nick-lane.net/publications/origin-life-alkaline-
| hydr...
| adampwells wrote:
| There is a podcast interview [1] with Nick Lane by Sean
| Carrol that goes into more detail along these lines - a very
| compelling argument!
|
| [1]https://www.preposterousuniverse.com/podcast/2022/05/23/19
| 8-...
| zmgsabst wrote:
| > (And yes, the enzymes I refer to could be realized as RNA,
| but acting as the enzymes directly, not merely describing them,
| and this would confer some major benefits)
|
| Isn't the standard model that chemical complexes of increasing
| sophistication formed around volcanic vents until the molecules
| involved looked like viroids or other ribozymes?
|
| Then there's an evolutionary fork, where the RNA moves towards
| DNA for storage and proteins for work, but the relationship
| remains mediated by RNA, eg in mitochondria.
| Ultimatt wrote:
| The RNA thing is more about what was the first storage of
| genetic heritable information, I don't know anyone in academia
| who imagines some kind of RNA world where auto catalytic
| networks weren't established first or alongside... So yes?
| You're creating a weird straw man argument for yourself. No one
| doesn't agree with you. That doesn't take away from the idea of
| stored information being in RNA before say DNA as it is today.
| Some of the more fun theories I've seen also focus around the
| ribosome as the original primary replicator rather than cells.
| With cells being the evolutionary consequence of ribosomes
| improving their efficiency.
| greenbit wrote:
| Maybe it's the sources I look at, which unfortunately tend to
| be journalistic rather than scientific. So I encounter
| something like 10x as many items about RNA/DNA for every one
| about abiogenesis that focuses on something else.
| nradov wrote:
| For those interested in the chemical origins of life, the Lex
| Fridman podcast has a fascinating interview with University of
| Glasgow chemist Dr. Lee Cronin who has done some of the
| fundamental research in this field. It's long but worth a listen.
|
| https://lexfridman.com/lee-cronin/
| photochemsyn wrote:
| Interesting work. One thing to keep in mind is that early
| environments were anoxic, as free oxygen only arose after the
| development of photosynthesis on a global scale. This should have
| made abiotic synthesis relatively easier as oxygen acts as kind
| of bleach (production of OH radical etc.), so it's likely early
| oceans were awash with a wide variety of organic molecules, as
| well as tons of dissolved iron and sulfur species, likely
| phosphorous as well.
|
| People have also described a wide variety of catalytic activities
| with carbon dioxide and hydrogen catalyzed at hydrothermal vent
| environments by metals, such as the formation of small aldehydes
| and ketones (short-chain/branched carbon molecules with double
| bonds incorporating an oxygen atom) which can then go on to
| participate in other reactions with ammonia and hydrogen
| plausibly leading to amino acids. Another simple abiotic reaction
| is the formation of hydroxlamine (H2N-OH) which can feed into the
| synthesis of the simple ring structures of nitogenous bases (the
| components, plus five-carbon sugars, of the A,U,C,G's of RNA).
| See:
|
| Unified prebiotically plausible synthesis of pyrimidine and
| purine RNA ribonucleotides (2019)
|
| https://www.science.org/doi/10.1126/science.aax2747
|
| Abiotic synthesis of amino acids in the recesses of the oceanic
| lithosphere (2018)
|
| https://www.nature.com/articles/s41586-018-0684-z
|
| Both those articles are on sci-hub.se for those interested.
|
| One interesting speculation is that RNA and protein developed
| more or less simultaneously, and that short protein chains were
| affiliated with short RNA chains from the very beginning. This
| could plausibly result in a proto-ribosomal entity capable of
| self-replication using the abiotic pool of nucleosides and and
| amino acids as raw material. This idea has been around for ~20
| years, here's something recent on it:
|
| A prebiotically plausible scenario of an RNA-peptide world (May
| 2022)
|
| https://www.nature.com/articles/s41586-022-04676-3
|
| These kinds of reactions would seem to be quite plausible on
| other worlds with a liquid ocean. Also, they had millions of
| years to develop, meaning low-probability events aren't ruled
| out. Life is probably widespread in our universe.
| dukeofdoom wrote:
| So is the spike protein shedding real. I've learned in school
| that viruses directly exchange genetic information with each
| other. The possibility of wild RNA coming from the environment
| would be something new.
| AndrewDucker wrote:
| Critically, formed from ribonucleoside triphosphates. This is an
| important step, but there are others needed to give us the
| complete chain of generation.
| BiteCode_dev wrote:
| Yes, but it does hint that spontaneous emergence of basic life
| building blocks is a more and more viable hypothesis.
|
| And that, given similar conditions, other worlds could develop
| ecosystems analogue to ours.
| sockpuppet_12 wrote:
| Theorising that high carbon steel can form by mistake in some
| scenarios is no where even remotely close to the information
| management necessary to spontaneously create a tesla.
|
| And even a Tesla is no where remotely close to the organic
| cell. The smallest known functional, and most importantly,
| stable biological unit.
|
| Even if rna is formed, what will read it?
| BiteCode_dev wrote:
| Those are good questions, but having questions doesn't
| decrease my interest, it just gives it context.
| gus_massa wrote:
| > _Even if rna is formed, what will read it?_
|
| That's the interesting part of RNA. You don't need a
| reader!
|
| RNA can act like an enzyme. They can fold and form strange
| shapes and have some "sticky" parts, so they can replace
| the activity of enzymes. Enzymes made of proteins are more
| efficient, so now most(all?) enzymes are made of proteins.
| But in the initial form of life perhaps enzymes were just a
| short RNA strip.
|
| RNA can be copied. They can be in a single strain, and they
| can collect the parts [1] and make an inverse copy, and
| then separate. DNA is better with a lot of helper enzymes
| is much better, but in the initial form of life perhaps RNA
| is good enough.
|
| None of these steps need a reader, so perhaps they can form
| an initial and very inefficient life(almost-life) form.
|
| [1] the parts:
| https://en.wikipedia.org/wiki/Nucleoside_triphosphate
| doctoboggan wrote:
| This is a very interesting result. Does anyone know how likely
| ribonucleoside triphosphates are to be formed in young earth
| conditions? What is the state of the research on this topic?
|
| It seems like this is a pre-print but if it stands up to peer
| review this would appear to be a big step forward in our
| understanding of abiogenesis, and would seem to be good evidence
| for the RNA world hypothesis.
|
| I always kind of hoped abiogenesis happened multiple times on
| multiple worlds, rather than once and then spread through
| panspermia. This result seems to indicate it could have happened
| here.
| greenbit wrote:
| Wouldn't it be fascinating if it happened multiple times right
| here on earth, even.
| 41b696ef1113 wrote:
| Even if it were possible to happen repeatedly wouldn't the
| prior generation be immediately able to out compete
| (immediately consume) the nascently developed life?
| Scramblejams wrote:
| Makes me wonder how abundant basalt lava glass is on planets in
| the goldilocks zone.
| Cannabat wrote:
| I believe submission title is inaccurate:
|
| > This study shows that various mafic rock glasses almost
| certainly present on the surface of the Hadean Earth catalyze the
| formation of polyribonucleic acid in water starting from
| nucleoside triphosphates.
|
| > Thus, the prebiotic relevance of this result very much depends
| on whether nucleoside triphosphates were present to Hadean impact
| fields.
|
| In other words, RNA spontaneously forms on basalt lava glass in
| the presence of nucleoside triphosphates. These are compounds for
| which there is no known prebiologic formation process - we only
| know of nucleoside triphosphates as compounds created by living
| organisms.
|
| Disclaimer: I am not an expert in this area, I just read the
| article.
| uplifter wrote:
| I trained as a biochemist and you nailed it. The submission
| title's claim is wildly more extraordinary than the actual
| result. It's like claiming "Lines of humans spontaneously
| appear on a hot tin roof" when what happened was "humans
| spontaneously link arms when placed upon a hot tin roof."
| Layke1123 wrote:
| Seems more reasonable a claim than life was breathed into
| clay to form man.
| natpalmer1776 wrote:
| I mean, if you imagine life on earth originated as a petri
| dish experiment by some advanced species the whole
| "breathed life into clay" might not be so far fetched,
| given some allowance for numerous translation context
| changes.
| Layke1123 wrote:
| Right, because those petri dishes definitely had language
| that captured how it came to be.
|
| Here is the difference. If it is as you say, then people
| go reasonable.
|
| If we suggest it truly was spontaneous and without
| direction, people cry, "Bigot! Heretic! Why are you SO
| INTOLERANT!"
|
| Shove off with your apologetics.
| Thorentis wrote:
| Honestly, I've never had a Creationist call me a bigot
| for wanting to debate them. In fact, they usually welcome
| to the debate and see it as an opportunity to convert
| somebody. The only time I've ever seen name calling is
| when an angry anti-theist lashes out at somebody for not
| trusting science, or when comments like yours use them as
| a straw man.
| Layke1123 wrote:
| Can I introduce you to some people then? I would love to
| drop you off in other places too, not just here in the
| US, but Saudi Arabia or Afghanistan and let's seem if
| your claim holds true. Care to take me up on the offer?
| dotopotoro wrote:
| conflating "creationists" to societies which dont
| recognize women as individual person..
|
| is technically correct. The best kind of correct of
| course. But also a bit of blow below the belt.
|
| (Especialy when there are plenty of shouting religious
| politicians, that could have been used in your argument)
| Layke1123 wrote:
| No, what it is is an acknowledgment that there are people
| who think rationally, and then there are those people who
| think you should fucking shut up and be burned at the
| stake for disagreeing with them. The idea that modern
| anti-theists are anything like our current theistic
| members of society is laughable, and honestly starting to
| make me wonder who cares if we turn into them.
| xabotage wrote:
| You're saying scientific processes (petri dish
| experiment) may have created life because we can't yet
| explain what scientific processes may have created life?
| And ancient, unscientific mythological fairy tales may
| somehow have encoded this event, despite having always
| been taken at face-value up until they were
| scientifically and rationally disproven?
| MichaelZuo wrote:
| The original title is much less clickbaity ' Catalytic
| Synthesis of Polyribonucleic Acid on Prebiotic Rock Glasses'.
| Maybe one of the mods could change it since it's not
| following the site rules anyways.
| ianai wrote:
| But is that original title going to properly convey
| significance to non-biologists/the lay audience?
|
| Coming up with good titles that will survive the HN
| thoughtchamber is not easy.
| IncRnd wrote:
| The existing, clickbaity title claims a significance that
| doesn't exist.
| natch wrote:
| >we only know of nucleoside triphosphates as compounds created
| by living organisms
|
| That is your claim. But the article claims, and I'm not saying
| it's true, I also am not an expert... but it's an interesting
| claim:
|
| "many proposals are emerging describing how triphosphates might
| have been made on the Hadean Earth"
| gus_massa wrote:
| Triphosphates are like tiny "batteries". A lot of important
| reactions in a cell are just moving the third phosphate to
| another molecule to "move" the stored energy and do something
| useful later, or to move the third phosphate back to charge
| again the "battery".
|
| So it's not expected to have a lot of _charged_ batteries
| floating around. IIRC there are some non-biological process
| that produce triphosphates, but the amount is tiny^n. In a
| life-less world, is the production speed enough to make them
| accumulate until there the concentration is high enough for
| this reaction? Or they break before they can form RNA chains?
|
| Also, IIRC there are some alternative proposal for the
| formation of the first RNA. All are horrible slow an
| inefficient. Is this new method slightly less slow and
| slightly more efficient?
| Cannabat wrote:
| Sure is an interesting claim. Key words include "proposals",
| "emerging", and "might" - sounds like we have not
| demonstrated any of those processes just yet, but the people
| who know what they are talking about think abiogenesis is
| possible.
| dylan604 wrote:
| In all scientific research someone comes up with a theory
| that proposes an idea as it emerges that might do
| something. It is science's job to the then test that theory
| to either prove or disprove it. The problem is that from my
| armchair quarterback role that these theories are getting
| submitted and then published in the media before any
| testing has been done. Which can be okay as maybe that will
| bring it to the attention of someone in a position to
| actually do the testing. However, it tends to come off
| sound like it is fact or widely accepted as true
| prematurely by some of the shoddy reporting
| pmayrgundter wrote:
| Also not expert.. I was looking around for the precursors and
| found that Ribose has been detected in meteorites[1]. That
| seems to leave finding prebiotic sources of the nucleobases,
| purine and pyrimidine.[2] Seems this is known, tho haven't seen
| a natural catalytic pathway to combine them into a nucleoside.
|
| Purine can be synthesized from Formamide via simple heating[3],
| and Formamide is common enough that it's hypothesized as an
| alternative to water, for a universal solvent in
| exobiology.[4,5]
|
| So, easy enough! ;)
|
| As remarked in sibling, it seems the harder step is the
| energetic bump up to a triphosphate.
|
| [1] https://en.wikipedia.org/wiki/Ribose [2]
| https://en.wikipedia.org/wiki/Nucleobase [3]
| https://en.wikipedia.org/wiki/Purine#Laboratory%20synthesis
| [4,5] https://en.wikipedia.org/wiki/Formamide
| https://en.wikipedia.org/wiki/Hypothetical_types_of_biochemi...
| hammock wrote:
| Still pretty cool. It's helpful to know the conditions (and
| therefore planetary eras, etc) that catalyzed the development
| of more advanced lifeforms, to the extent that it dials in a
| more robust understanding of how our present ecology came to be
| adrian_b wrote:
| Yes, that is exactly the problem.
|
| It is an interesting result that there is spontaneous
| polymerization catalyzed by volcanic rock glasses, but this is
| an extremely simple reaction, which is expected to happen
| spontaneously in various conditions.
|
| Making the monomers, i.e. the nucleoside triphosphates,
| requires a long chain of complex reactions, and also energy.
|
| There is no doubt that RNA has first appeared accidentally, by
| spontaneous polymerization of nucleoside triphosphates, but
| those must have been produced by an already existing form of
| life, which had to use a continuous source of energy for
| complex molecule synthesis, e.g. dihydrogen, carbon monoxide
| and a ionic concentration gradient, which can be provided by
| submarine vents.
|
| While the study does not offer any new information about the
| actual origin of life, the first accidental synthesis of RNA
| must have used some catalyst and that catalyst might have been
| a component of volcanic rocks, as shown in this study.
|
| Only after some molecules of RNA with random composition
| already existed, due to spontaneous polymerization, it could
| happen for a RNA molecule to serve as a template for
| replication, during the polymerization of another RNA molecule.
| Therefore it is important to determine in which conditions the
| polymerization of RNA can happen, in the absence of specialized
| enzymes.
| dang wrote:
| Ok, we've used your phrasing to replace the submitted title
| ("RNA spontaneously forms on basalt lava glass (abundant on
| Earth 4.35B years ago)"). Thanks!
| shawnz wrote:
| Surely it goes without saying that the process only happens in
| the presence of the right precursors?
| lupire wrote:
| Consider the difference between
|
| "Spontaneous appearance of human life in sealed room" and
| "Spontaneous appearance of human life in a sealed room
| containing two humans."
| [deleted]
| Metacelsus wrote:
| >This polyribonucleic acid averages 100-300 nucleotides in
| length, with a substantial fraction of 3',-5'-dinucleotide
| linkages
|
| Notably they don't distinguish linear vs. branched RNAs, it's the
| linear ones which are likely to be more interesting for the
| development of life.
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